Eminence Kappa Pro 15A modeling / midrange questions...

[christw]

I snagged a "bass cab" with an Eminence Kappa Pro 15A in it for $100 as my beater cab to leave in my car's trunk. I want to model it to get an idea of its performance in that particular box. This isn't a bad sounding cab but I haven't really pushed it hard enough to find any quirks.

Here's where you guys come in! I'm going to start messing with WinISD but I'd rather ask someone who knows their stuff to quickly model the speaker/box combination for me to give me an idea of performance. (Not to mention I can't seem to figure out where/how to get the specs on that particular driver for WinISD!) Secondly, I wanted to know what a good midrange compliment would be and how lazy and cheap I can be with the design.

Cab dimensions coming up as soon as I run outside with a tape measure.

Thanks y'all. You guys are always a huge asset to me and each other when it comes to this thing!

Just for the fun of it, here's the cab. The pad is labeled as a mid range but I haven't got a good feel for the driver. I'll report back after rehearsal tomorrow if I can. I'll probably dissect the cab to find out exactly what else I've got in there too...

 

[christw]

Inner dimensions are approximately 22.5 x 22.5 x 10" with two 4" diameter by 6" long tube ports.

 

[DukeLeJeune]

I come up with 52 Hz ballpark tuning frequency, assuming a net internal volume of 2.6 cubic feet (after subtracting for woofer and ports).

 

[billfitzmaurice]

I can't seem to figure out where/how to get the specs on that particular driver for WinISD

Speaker Detail | Eminence Speaker

 

[christw]

Thanks guys! I think I just need to learn how to use WinISD now... I keep messing around with it but it's slow going.

 

[bassmeknik]

I have limited experience with WINISD but if I did this correctly your dimensions and port sizes will work out to a box tuning frequency of about 50hz. This configuration will have a -3db point at 67hz and a -10db point at about 43hz (approximately).


In my limited experience I think the box is to small to make a good stage bass cab, I think the cab should be about twice as large in volume to get the most from this driver. There are many on TB with much more experience than myself such as BFM and greenboy, Hopefully they will find this thread and comment.

 

[bassmeknik]

I see Mr Fitzmaurice has been here while I was doing my research. Could you comment on my math and box opinion sir?

 

[billfitzmaurice]

If I was to use one it would be in 4-4.5 cu ft net tuned to 50 Hz. Smaller will be a bit boomy in the midbass and weaker in the lows.

 

[christw]

bassmeknik, I'm getting similar numbers to you now that I've got the hang of it. I ran the cab hard on the low end with a six string ESP LTD and a Peavey Tour 700 before buying it. It definitely fits Bill's description. I think it'll suffice for now although I won't disagree with those of you who say it can be improved.

 

[bassmeknik]

Thank you Bill, Hey christw try plugging in the box volume Mr Fitzmaurice suggested and get a look at how it affects the response. It will look startlingly different than your existing box at the bottom end. (Much more low bass output)

 

[christw]

I just did and wow, that makes a difference! I might build a cab around this driver later but for the moment I'm going to have to live with it how it is. It fits in the car's trunk and gets loud-that's all I'll ask of it for now.

 

[DukeLeJeune]

The Kappa Pro 15A has fairly modest excursion, so its fartout-limited power handling isn't all that great. Yes a bigger box will go deeper (meaning, it will be more efficient at low frequencies), but the woofer will still run out of excursion at about the same SPL as a similarly-tuned smaller box.

 

[walterw]

i gotta say, i'm really pleased with the kappa As in my two little 1x15 boxes!

LDS don built them for me, and i think i did it in the right order: "hey don, can you build me a little rock & roll cab that'll work with these 15As i have? cool, build me two of them!"

they don't go super deep or anything, but they're loud and proud with plenty of presence for my grindy P-bass>pick>sansamp rock bass stylings; i often go PA-less in bars and small clubs with them.

 

[Alex Xander]

I come up with 52 Hz ballpark tuning frequency, assuming a net internal volume of 2.6 cubic feet (after subtracting for woofer and ports).

Based on Duke's figures - here is how it models. A picture tells a thousand words, although as others have said xmax is small.

Link Removed

EDIT: Whoops, I clipped off the frequency scale. The origin is 10hz

 

[billfitzmaurice]

The Kappa Pro 15A has fairly modest excursion, so its fartout-limited power handling isn't all that great. Yes a bigger box will go deeper (meaning, it will be more efficient at low frequencies), but the woofer will still run out of excursion at about the same SPL as a similarly-tuned smaller box.

True. Unless you really need the additional low frequency extension there's not a lot to be gained with a larger box, unless the midbass hump is causing problems that your amp EQ can't compensate for. But an amp that can do so seamlessly would be the exception. IMO the most important EQ function is a sweepable frequency midbass notch filter, nominally centered around 100Hz, that allows you to notch out boom in the midbass without killing your lows too, which is all you can achieve with a typical bass shelving EQ.

 

[christw]

Well, I'll run it with the band tonight and see how it sounds. I don't think I'll have any issues with this cab as is. I tend to bring down the lows and bump around 120 hz on a lot of cabs.

 

[punchclock]

Kappa Pros sound really good in a TL-606 with the port cover. Solid.